The usual fix is to remove the songs from the iPod, then put the songs back on.
If this doesn't fix it, then I would like to know what the format of the file is (MP3, M4A, M4B, M4P).
If it is an MP3 then you should update the ID3 tags in iTunes.
Select the song in iTunes, then click File->Convert->Convert ID3 Tags
- Choose version 2.3
- Wait for iTunes to write the Get Info information into the MP3 files
Then put the songs back onto the iPod.